Problem: A circle with circumference ${6}$ has an arc with a $60^\circ$ central angle. What is the length of the arc?
Answer: The ratio between the arc's central angle ${\theta}$ and $360^\circ$ is equal to the ratio between the arc length ${s}$ and the circle's circumference ${c}$. $\dfrac{{\theta}}{360^\circ} = \dfrac{{s}}{{c}}$ $\dfrac{{60}^\circ}{360^\circ} = \dfrac{{s}}{{{6}}}$ $\dfrac{1}{6} = \dfrac{{s}}{{6}}$ $\dfrac{1}{6} \times {6} = {s}$ $1 = {s}$ ${6}$ ${60^\circ}$ ${1}$